This invention relates to a multi-layer toroidal deflection yoke including front and rear ring members for retaining conductor turns.
It is known that precision and repeatability can be achieved in winding toroidal deflection yokes for television receivers by retaining each conductor turn of a given winding distribution in grooved ring members located at the front and rear portions of the deflection yoke core. The technology making this precision winding possible has permitted deflection yoke designers to utilize specific winding distributions for providing self-converging and raster correction features in the deflection yoke itself, resulting in less complex television receiver designs.
Particularly when these precision toroidal deflection yokes are utilized with relatively large screen size picture tubes having relatively wide deflection angles such as 110.degree., it may be necessary to add additional conductor turns to enhance the sensitivity of the vertical deflection coils or to add additional conductor turns for forming quadrature windings to aid in converging the three beams of a color picture tube when the windings are suitably energized. To accommodate a relatively large number of conductor turns, it has been the practice in the past to wind multiple layers of turns, with the succeeding layers of conductor turns at the small diameter portion of the yoke lying above and interleaved between conductor turns of the next preceding layer. However, these turns flare outwardly towards the large diameter portion of the yoke, resulting in more spacing between conductors so specific grooves in the large diameter ring member must retain each conductor turn. As the number of conductor turns increases, the radially extending tabs defining the conductor turn retaining grooves must necessarily become thinner. Eventually a point is reached whereat the tabs are so thin that the molding thereof becomes difficult as the plastic ring member material does not flow readily into the small crevices of the mold. Even should molding be successful, the tabs are so thin that a lateral stress on the tabs such as caused by returning the conductor turn at a nonradial angle along the outside surface of the yoke may cause the tabs to bend, thereby possibly resulting in the conductor turn slipping out of its groove or the bent tab preventing the entry of another conductor turn in the next adjacent groove. Obviously it is desirable to provide an arrangement for precision placement and retention of the conductor turns.